NOLATHANE Fifth Wheel Bushing

Nolathane fifth wheel bushings replace the worn cushions between a semi truck?s fifth wheel top plate and its mounting bracket. These 5th wheel bushings carry the pivot that lets the top plate rock as the tractor and trailer move. Renewing them removes the slack, clunks, and metal-to-metal wear that build up as the original material breaks down.

Made from polyurethane for a heavily loaded joint that never stops moving, the bushings suit fleet shops, owner-operators, and heavy-duty repair shops servicing tractor-trailer combinations. Each listing shows the fifth wheel models the kit is cross-referenced to, along with the kit contents.

The Role of the Fifth Wheel Pivot

A fifth wheel is the coupling that connects a tractor to a semi-trailer. The trailer?s kingpin locks into jaws under the top plate, and the front of the trailer rests on the plate?s greased surface.

The top plate doesn?t sit rigidly on the frame. It rides on a pair of brackets, held by bracket pins that let it rock fore and aft. That articulation allows the plate to follow the trailer as the rig climbs a grade, crests a hill, or rolls over a dock approach or rail crossing, keeping the load spread across the whole plate rather than concentrated on its front or rear edge.

The bushings fit around the bracket pins and carry that motion. They cushion the pivot, keep each pin centered in its bracket, and stop steel from rubbing on steel every time the plate rocks. On a truck covering long highway miles, that pivot cycles constantly under some of the heaviest loads anywhere on the vehicle.

Signs of Worn Fifth Wheel Bushings

Fifth wheel bushings wear gradually, so symptoms often build for months before a driver reports them. Look and listen for:

• A clunk or bang from the coupling when starting off or braking
• Excess fore-aft rock in the top plate with the trailer uncoupled
• Slack or a jerking sensation felt through the cab as the trailer pushes and pulls
• Cracked, extruded, flattened, or missing bushing material at the bracket
• Bracket pins that look polished, stepped, or worn oval

Not every bang from the coupling comes from the bushings. Kingpin wear and locking jaw slack produce similar symptoms, and they need their own adjustment or repair. Checking the bracket pivot separately from the lock saves replacing parts that were never the problem.

Inspecting the Fifth Wheel Mount

The best time to check fifth wheel bushings is during scheduled preventive maintenance (PM) or a routine fifth wheel inspection, when the trailer is already uncoupled and the plate has been cleaned.

Start with a visual check of both brackets. Healthy bushings fill the space around the pin evenly, while worn ones show gaps, splits, or material squeezed out of the bracket. Rust-colored dust around the pivot means metal is already wearing against metal.

Next, check for play. With the trailer uncoupled, place a pry bar between the top plate and the bracket and lever the plate up and fore and aft. Some rocking is normal because the plate is designed to articulate, but vertical lift or a knock at the bracket points to worn bushings or pins. Compare what you find against the play allowance the fifth wheel maker specifies, and note it in the maintenance log so the trend is visible from one PM to the next.

Finally, look closely at the pins. A pin with a groove or flat spot will chew through new bushings quickly, which is why pin condition matters as much as bushing condition. On greasable designs, confirm the pivot is getting grease at the interval the maker recommends, because a dry pivot wears far faster than a lubricated one.

Polyurethane and Rubber Fifth Wheel Bushings

Original-equipment bushings are often rubber, which cushions the pivot well when new. Over time, rubber softens with heat, swells with grease and oil, and cracks from ozone and weather exposure, so it gradually loses its shape and lets the pins wander.

Polyurethane copes with those conditions better. It offers outstanding abrasion resistance against a rocking steel pin, high load-bearing capability under a loaded trailer, and resistance to the grease, oil, ozone, and road weathering a fifth wheel lives in. It also recovers its shape after compression, so the bushing keeps holding the pin through constant cycling rather than taking a permanent set.

Hardness matters on a pivot this heavily loaded. Nolathane selects the durometer, or hardness grade, for each application, so a fifth wheel bushing is firm enough to resist extruding under load while still cushioning the rocking motion. Rubber remains a reasonable choice for operators who want the softest feel, but in high-mileage fleet service it typically needs replacing more often.

Matching a Fifth Wheel Bushing Kit

Fifth wheel bushing kits are specific to the fifth wheel model rather than the truck, so the hitch, not the tractor, decides what fits. Each listing shows the cross-referenced part number, the fifth wheel models covered, and what the kit contains.

Fifth Wheel Model and Part Number Cross-Reference

Find the model and part number on the fifth wheel?s identification tag or in the maintenance records, then match the fifth wheel maker?s number to the cross-reference shown in the listing. If the tag is missing or unreadable, measure the existing bushing and pin before ordering, since similar-looking fifth wheels can use different sizes.

Bushing Position and Kit Contents

Most fifth wheels use bushings at both brackets, and they should always be replaced as a set so the plate pivots evenly. Check the listing to see how many bushings the kit includes, and order enough to cover every position on the fifth wheel.

Pin Condition

Bracket pins wear along with the bushings. New bushings installed over worn pins are loose from the first mile and wear out early, so replace any pin that is grooved, stepped, or out of round, together with its retainers.

Replacing Fifth Wheel Bushings

The fifth wheel coupling is safety-critical, so replacement is best handled by a qualified heavy-duty technician or a fleet shop with suitable lifting equipment. As a general guide:

1. Uncouple the trailer, park the tractor on level ground, and chock the wheels.
2. Support the top plate securely with lifting equipment rated for its weight.
3. Remove the pin retainers and drive out the bracket pins.
4. Lift the top plate clear, remove the old bushings, and clean rust and scale from the bracket bores.
5. Install the new bushings, using new pins and retainers wherever the old ones are worn.
6. Lower the plate into position, refit the pins, and secure the retainers.
7. Grease the pivot and top plate as the fifth wheel maker specifies, and torque all fasteners to specification.
8. Recheck fastener torque and pivot play after the first few trips.

Cleaning the bracket bores is the step most often rushed. A rough, corroded bore wears a new bushing faster than highway miles ever will.

Limitations and Trade-Offs

New bushings fix one specific problem, so it helps to be clear about what they won?t do:

• They remove pivot play only and don?t adjust or repair locking jaws, kingpins, worn top plates, or cracked brackets
• Polyurethane is firmer than rubber, so the driver may feel slightly more coupling movement in the cab
• Each kit fits only the fifth wheel models shown in its listing
• They aren?t designed for the fifth wheel hitches used to tow RVs and travel trailers with pickups

That last point matters because the names overlap. Pickup-mounted fifth wheel hitches for recreational towing are a different product with different hardware, while these bushings are made for commercial semi truck fifth wheels.

Commercial Vehicle Inspections and Insurance

The fifth wheel is checked in every commercial vehicle inspection, and the coupling must meet the federal and state requirements that apply where the truck operates. Loose or worn mounting components are among the items inspectors look at, so tired bushings can affect an inspection result as well as how the truck drives. Record the work in the maintenance log, and tell your insurer about any modifications to the vehicle.

Warranty and Support

Nolathane fifth wheel bushings are covered for life against defects in material and workmanship on the tractor they were first installed in. If the fifth wheel tag is hard to read or you want to double-check a cross-reference, our local support team can help confirm the right kit before you order.

Shop Fifth Wheel Bushings

Fifth wheel bushings are listed in the Nolathane polyurethane bushings selection.

Order the kit cross-referenced to your fifth wheel model and it goes out with fast shipping. Our fitment guarantee covers the match to the fifth wheel models shown in the listing. Many fleet shops keep a kit on the shelf, so a worn pivot found at PM can be repaired the same day instead of waiting on parts.